I am getting a lot of black on the back of my car. I have a jrsc with just the JR MAP controller and BTC. I know that this set up runs rich, but I was wondering if retarding the timing keeps the exhaust valves open during compression. At max boost (8 psi) the timing is retarded about 6.4 degrees. Could this be why my exhaust is so dirty or is it just because my A/F is so rich. I am not burning any oil that I can tell.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fredtoast &raquo;</TD></TR><TR><TD CLASS="quote">... I was wondering if retarding the timing keeps the exhaust valves open during compression. At max boost (8 psi) the timing is retarded about 6.4 degrees...</TD></TR></TABLE>
Is your exhaust camshaft timing retarded or is your ignition timing retarded? I bet it's ignition timing. That has nothing to do with keeping your exhaust valve open.

 

You're right. I never thought about that. The camshafts' timing to the crank have not been changed. The BTC only controls the ignition timing. Thanks.